Heart valve disease continues to be a significant cause of morbidity and mortality, resulting from a number of ailments including rheumatic fever and birth defects. Currently, the primary treatment of aortic valve disease is valve replacement. Worldwide, approximately 300,000 heart valve replacement surgeries are performed annually, and about one-half of these patients received mechanical heart valves, which are composed of rigid, synthetic materials. The remaining patients received bioprosthetic heart valve replacements, which utilize biologically derived tissues for flexible fluid occluding leaflets.
The most successful bioprosthetic materials for flexible leaflets are whole porcine valves and separate leaflets made from bovine pericardium stitched together to form a tri-leaflet valve. However, flexible leaflets formed of polymeric, fiber-reinforced, and other synthetic materials have also been proposed. The most common flexible leaflet valve construction includes three leaflets mounted to commissure posts around a peripheral non-expandable support structure with free edges that project toward an outflow direction and meet or coapt in the middle of the flowstream. A suture-permeable sewing ring is provided around the inflow end.
Bioprosthetic heart valves are packaged in jars filled with preserving solution for shipping and storage prior to use in the operating theater. To minimize the possibility of damage to the relatively delicate bioprosthetic heart valves, they are stabilized with bracketing structure to prevent them from striking the inside of the jar. Prior to implantation in a patient, the valve is removed from the jar and then rinsed in a shower or immersed and agitated in a bath.
The majority of prosthetic valves are destined for either the mitral or aortic position, though to a much lesser extent tricuspid and pulmonary replacements are made. The conventional surgical delivery path for mitral and aortic replacements is from above; down the right atrium for mitral valves and down the ascending aorta for aortic valves. (Of course, these directions are relative to the upright human, and with the patient lying supine up and down become horizontal). The blood flow direction in these two positions is opposite, with blood flowing down from the right atrium through the mitral valve and into the left ventricle, and then up from the left ventricle through the aortic valve and into the ascending aorta. Therefore, the mitral valve is normally distally advanced with the inflow side up (or proximal), and the aortic valve is advanced with the outflow side up. Prosthetic valves typically have a valve holder centrally located and sutured thereto, and the holders used for both are attached to the proximal end—to the inflow sewing ring for mitral valves and to the outflow commissure tips for aortic valves—so that an attached surgical delivery handle extends proximally out of the implant site. The delivery handle usually couples to the valve holder while still in the jar and lifts the valve assembly out of the jar. Consequently, to orient the mitral valve holder facing upward in the jar the outflow leaflet commissure tips project down, while the jar orientation for aortic valves is with the inflow sewing ring extending down into the jar. Both valves are thus suspended downward from the holder into the fluid-filled jar, though inverted with respect to one another.
The valves are stabilized with various structures, including a 2- or 3-piece clip and tubular sleeve structure, such as shown in U.S. Pat. No. 6,416,547 to Erickson, et al. One function of the sleeve is to create an annular space between it and the jar for receiving a product ID tag dangling from the valve by a thread and prevent it from contacting and potentially damaging the valve leaflets. This packaging configuration is somewhat complex and time consuming to assemble and disassemble, and is somewhat limited by the aforementioned respective jar orientations for mitral and aortic valves.
In view of the foregoing, it is apparent that there is still a need in the art for alternative packaging for heart valves that enables a medical practitioner to easily and safely remove the valve, as well as attach a surgical handle thereto.